


Where The Sky Meets The Sea

by Sanjuno



Series: Ideas of March 2018 [13]
Category: Katekyou Hitman Reborn!, One Piece
Genre: ASL Brothers, ASL are all Skies, ASL brothers are reborn as Tsuna's little brothers, Also through Harmony, Everything is Beautiful and Nothing Hurts, F/M, Gen, It was a surprise to everyone else too, Not that the Mafia knows that, Pirates in the Mafia, Reincarnation, Responsible Parent Sawada Iemitsu, Sawada!ASL, Tsuna becomes a D through osmosis, Tsuna is Not Dame, Tsuna is tired of putting out fires, Tsuna never gets Sealed, Why is the world so flammable?, Xanxus never gets frozen, no Cradle Affair
Language: English
Status: Completed
Published: 2018-08-26
Updated: 2018-08-26
Packaged: 2019-07-02 22:26:28
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,082
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15805776
Author URL: https://archiveofourown.org/users/Sanjuno/pseuds/Sanjuno
Summary: The children of the Sea have always chased after the horizon with a fire in their hearts that drove them ever forward to reach the place were the sky kisses the water. Not even death can stop the Will of D from echoing across the world.Sawada Tsunayoshi is the responsible older brother to three wild and mischievous little brothers. Tsuna loves them and they love him back. Now if only the world around them would stop catching fire so easily all the time, that would be fantastic.(The Will of D joins with the Flames of Sky in a Harmony that will bring forth the storm of change.)





	Where The Sky Meets The Sea

**Author's Note:**

> This might be a little confusing, because it's written entirely from various Outsider POVs of the ASL brothers reborn as the younger Sawada kids. But it's also fantastic because these little shits give no fucks and its glorious. ♥

=/=

Sawada Nana’s husband Iemitsu was a hardworking man who had to travel overseas more often than not. His job working as an auditor for an international conglomerate paid very well, but it kept him away from home. Still, Sawada Iemitsu was there with Nana in the delivery room when their son Tsunayoshi was born.

Little Sawada Tsunayoshi was Nana’s son right down to his toes, and Iemitsu was smitten.

Staying home with his wife was no hardship, and Iemitsu delighted in everything his newborn son did. Sometimes the burning energy inside Iemitsu built up to the point he was worried about breaking something, but Iemitsu always managed to find an outlet. When their son was six months old exactly, Nana set their dinner plates down on the table and looked at her restless husband with a serene smile.

“Your paternity leave is just about up, isn’t it, darling?” Iemitsu froze, staring at Nana with wide eyes as she pressed her hands together in a brief thanks for the meal. “That’s why you’ve been so restless, right? Because it’s almost time for you to go back? It was good of your boss to give you so much time off for the baby. Please remember to thank him for me!”

“Ah, uh, of course! Hahaha! My Nana is so observant!” Iemitsu scrambled to collect his wits as his cheerfully smiling wife gave him the prefect out to explain his absences without breaking cover all but gift-wrapped. “I was worried about telling you, Nana, but it looks like you beat me to it!”

Iemitsu went back to work before the week was out, returning to his wife sporadically for a week or two every few months. This had consequences the couple really should have been expecting, because the Sawada’s relationship was only made more passionate by the time they spent apart. 

In another timeline Iemitsu might have been a little less enamoured of his son, a little less attached to his wife, a little more devoted to the process of rising through the ranks in the CEDEF. In another timeline, Iemitsu might not have been in his wife’s arms at just the right moment, but in this timeline he was. In this timeline he saw his wife more than once a year, and this made predictable changes to the world.

So when Tsunayoshi was two years old, they welcomed the arrival of Sawada Hidetada. The Sawada’s second son had the dark brown hair of Nana’s father, but the eyes obviously came from Iemitsu’s side of the family. Hidetada had inherited freckles from Iemitsu’s mother, but the rest of his face was mostly Nana’s.

Again, Iemitsu tried to work from home as much as he could for the first few months of his son’s life until there was no choice but to leave. Again, the couple was a little too enthusiastic about saying goodbye at the end of one of Iemitsu’s visits. To once again predictable results.

When Tsunayoshi was three years old, and Hidetada was one and three months, they welcomed the arrival of the Sawada’s third son Iesada. Although the shape of his eyes was Nana’s, Iesada had inherited his father’s blue eyes along with the blond hair.

Worried that his wife would be overwhelmed with caring for two toddlers and an infant when he went back to work, Iemitsu tentatively brought up the idea of taking measures to avoid having more children. Pouting a little, Nana agreed that it was the only sensible option they had. Iemitsu’s job was how they afforded their nice house and was why Nana could stay at home with her children all day, so Nana knew Iemitsu could not stay in Japan all the time just to help her.

So they were careful as they could be, to avoid any accidents. Only Iemitsu was a Sky who loved his wife and wanted to give her everything Nana’s heart desired. With that in mind, it was no wonder Nana ended up pregnant again.

When Tsunayoshi was six, Hidetada was four, and Iesada was three, they ended up welcoming the arrival of Sawada Yoshimune. Their fourth son had dark brown hair and eyes, and Iemitsu could only smile in hapless delight when his new son was placed in his arms.

/.../

Here is where the changes are growing. Iemitsu loves his wife, but he also knows how greedy the Mafia is for strong Skies. One son he might get away with having, four was out of the question. So Iemitsu never gave his son a name, never mentioned when the younger three were born. Iemitsu played the part of the cheerful idiot and let Nono maneuver him into position as the head of the CEDEF. Now removed from the succession, Iemitsu pretended to overlook the way Nono had relaxed considerably.

When Nono started making subtle mentions of meeting Iemitsu’s wife and son, it prompted a flood of babble about how his “cute little fish hated strangers”. It was enough for the moment, but Iemitsu knew better than to think that was the end of it. He needed something to distract Nono with, something to keep the old man’s attention focused firmly here in Italy and  _away_  from Iemitsu’s sons.

“... Xanxus is planning a coup.” Sandwich stuffed in his mouth, Iemitsu stared wide-eyed at the speaker relaying everything that was being said in Nono’s secret meeting with the Varia Cloud Officer. “I’ve got most of the plans, but we don’t have much time. It’s going to happen next week...”

Oh no. No. This was bad. This was  _so_  bad. Xanxus turning on him would make Nono  _unbearably_  paranoid. Iemitsu dreaded to think about the measures the old man would take to ensure Iemitsu’s children never became a threat to Nono’s legitimate heirs. Oh gods, he needed to do something.

Iemitsu’s tactic for stalling Nono about meeting his family had been  _working_ , damn it! Sure, it was only temporary, but Iemitsu would have come up with  _something_  better eventually! If only Ottavio were lying about Xanxus planning a coup then...

Hey. Now there was an idea.

/.../

Before Nono could call him in on prepping the Iron Fort defenses, Iemitsu gathered up all the scattered intelligence he had on the situation that had led to Enrico Vongola’s death and headed for Varia Headquarters. Breezing right by the men posted in the front hall, Iemitsu hummed a children’s rhyme as he honed in on Xanxus’ Flame.

“Goo~ood morning, cousin!” Iemitsu burst through the doors and ducked under the wine bottle that had been flung at his head without breaking stride. “I've come for a consult!”

“Ha?” Wow, Xanxus was looking a bit peaky. Iemitsu knew the teenager had been taking Enrico’s death hard, but Xanxus looked like he had not slept properly in weeks. “What the  _fuck_ , you trash...”

“We’ve got a few loose threads that need to be snipped, little cousin!” Smiling like he had no idea Xanxus wanted to kill him for the noise he produced, Iemitsu dropped the file down on Xanxus desk. Front and centre was the printed transcript of Ottavio’s meeting with Nono. Oops, how careless. Bad Iemitsu, you should keep things better organized. “Now, some of them just need a bit of a scare to straighten up, and the CEDEF will be handling that, but there are a few who have been telling tales to the wrong ears. I thought you and yours might be best suited to cleaning that side of things up.”

Xanxus glared at the printed proof that his plans were made and snarled. Maddened red eyes looked up at Iemitsu. “What the fuck are you about, trash?”

“Oh, you know how it is.” Iemitsu waved one hand vaguely through the air. “I do you a favour. You do me a favour. It all evens out in the end.”

Snorting, Xanxus leaned back in his seat and fished another wine bottle out from under his chair. “Talk.”

Pleased by the success of his plan, Iemitsu grinned.

/.../

There have been timelines where circumstances arrange themselves to allow Sawada Tsunayoshi to live free of the Seal that is placed on his Flames in so many of the other worlds. This timeline, however, is unique in the way Tsunayoshi develops his skill with his Flames and his Intuition. In this timeline, Tsunayoshi has three little brothers to take care of, and they are each the _embodiment of chaos given mortal form_.

Now, please know that Tsuna  _loves_  being a big brother. He likes being the one Hidetada comes to for cuddles when it’s naptime. He likes being the one Iesada goes to when the blond has questions. He likes being the one Yoshimune always asks first for a piggyback ride. Tsuna loves all of it, but he especially loves the way his little brothers adore him right back.

Despite the boisterous energy all four boys inherited from their father, Tsuna is actually fairly shy. Meeting new people and making friends was a somewhat daunting prospect, so Tsuna tended to focus most of his social attention on his little brothers and helping his mother around the house. So despite being a kind, admirable boy... Tsuna never actually made any friends his own age.

This was in retrospect a good thing, because the Sawada boys were a major contributing factor to the rapid response rate of Namimori’s fire department.

“This world is too flammable.” Tsuna grumbled for what was not the first time, patting out the fire that had taken hold of the grass with one hand while he handed his littlest brother a tissue with the other. Yoshi grinned at his eldest brother and blew his nose. “Why does everything catch fire so easily? It’s annoying.”

Sada and Hide exchanged a look and shrugged.

“It’s probably food poisoning.” Hide offered with a straight face.

Tsuna paused in brushing the ashes off his hands to stare at his little brother. “That... that makes no sense.”

“Yes it does.” Sada insisted, and Yoshi nodded rapidly in agreement.

/.../

When Tsuna is thirteen, Hide is eleven, Sada is ten, and Yoshi is seven, a baby wearing a fedora shows up at their house.

Flopped over on their stomachs on the bed behind Tsuna, the three younger Sawada’s stared at the tiny hitman over their eldest brother’s shoulders. For his part, Reborn was starting to think that someone, somewhere, had fucked up really,  _really_  badly. A single secret heir hidden among civilians was what the contract said. That was what the report from Vongola Nono had detailed. Not  _four_.

“A Mafia Boss.” The flat tone managed to imply a large amount of incredulity. Reborn was impressed by the eldest boy’s composure. Tsuna just looked irritated. “In what world is someone like me suited to being a Mafia Boss!”

“Is the Mafia like being a Pirate?” Yoshi asked with wide eyes.

“More like Gamma 66.” Sada replied absently as his gaze never left Reborn. “Or a criminal version of CP9.”

“And this is because of Dad’s bloodline?” Hide scoffed and dropped his chin onto his crossed arms with a scowl. “So he’s more like Roger than Dragon then. That sucks.”

“Shush.” Tsuna flapped a hand over his shoulder and narrowed his eyes at Reborn. “These pictures. Is this  _really_  what happened to the other heirs?”

“Yes.” Reborn is more curious than concerned. Iemitsu being enough of an idiot to miscount his own children is ridiculous but still believable. They were taking the news that their father was a criminal with surpassing aplomb too. Pity, Reborn had been looking forward to refuting his new student’s denials.

“And you’ve come  _here_. You’ve brought that threat  _here_ , to  _my little brothers_?” The autopsy photos went up in flames and it took every bit of control Reborn had not to show his shock. “ _How dare you_?”

“Ooo.” The littlest one looked delighted. “Niichan’s  _mad_.”

Well now. It looked like Iemitsu had been  _hiding things_  from Nono. This job just got  _vastly_  more interesting.

/.../

“I’ll serve you for life!” The bomber declared with all the reverent devotion of a newly converted fanatic. 

“Um.” Tsuna was concerned now. The other boy seemed to be a bit... desperate. Also a lot lonely, and with a gaunt look to his face that Tsuna sometimes saw on people who worked too hard and ate too little. “You don’t, um...”

“Niichan has a first mate!” Yoshi cheered from the top of the fence. Tsuna turned to see all three of his little brothers sitting beside Reborn and watching the new exchange student bow to Tsuna in the middle of the smoking crater the courtyard had become.

“Good job, niichan.” Sada clapped his hands slowly. “You’re growing as a person.”

“... I like him.” Hide said after a moment of staring at Gokudera critically. “He looks loyal and the explosions were cool.”

“Please stop helping.” Tsuna told his little brothers as Gokudera blinked up at them. Pulling the other teen to his feet, Tsuna kept a firm grip on Gokudera’s arm to discourage any more thoughts of dropping to his knees. That was just excessive. “You’re not actually helpful at all. Now, Gokudera-kun, would you like to come home with us for now? I don’t actually know how this works, you see, and I’d appreciate it if you could explain.”

/.../

“It’s too bad Niichan doesn’t have a swordsman.” Yoshi sighed as he swung upside down from his knees. “Every Captain needs a swordsman.”

“Oh?” For some reason, that caught the attention of their brother’s new friend. Yamamoto grinned up at the younger kids from his seat under the tree in the Sawada’s back yard. “Is Tsuna the Captain in this game?”

“Duh.” Hide snorted and looked down at the baseball player with distain. “Of course Niichan’s the Captain. Haven’t you been paying attention?”

“Hide-ni, be nice.” Sada chided without looking up from his book. “Yamamoto-sempai hasn’t been feeling well. It’s understandable that he might miss some of the details.”

“That’s enough out of all of you.” Tsuna frowned as he looked up from his textbook. “Stop distracting Yamamoto-kun from his studies.”

“Yes, niichan.” They pouted at having their fun interrupted, but they obeyed.

/.../

“Excuse me.” Dark chains fell slack to the ground as Tsuna stepped backwards, Mukuro’s limp body slung over his shoulder. “This happens to belong to me now.”

The Vindice stared, and Reborn manfully resisted the urge to hide his face. His student was oddly fearless about the  _strangest things._

“The convict Rokudo Mukuro will be returned to his cell.” The Vindice agent in the front rasped. “Stand aside or be incarcerated.”

“Loser serves the winner.” Tsuna was unmoved even as the nightmare of the Mafia approached him. “I won this fight, which means that Rokudo Mukuro and those who follow him belong to me now.”

The Vindice paused in their advance. Reborn stared. Well now. It looked like his student was a bit of a rules lawyer.

“You will be complicit in any further action he takes against the Mafia Code.” A dire warning, given what Rokudo was already guilty of.

“Oh, that’s fine.” Tsuna smiled, bright and happy and utterly self-assured. “I’m not worried about that.”

“... Very well.” The Vindice stepped back. “We will be watching, Vongola Decimo.”

“Hm.” Tsuna watched the Vindice disappear and boosted Mukuro’s body a bit higher on his shoulder. “Well, that was creepy.”

/.../

“It was nice of you to offer us dinner, Dino-san.” Tsuna blithely ignored the horrified shock growing on the faces of the Cavallone men as his little brothers rapidly consumed twice their own body weight in pasta, bread, and meat. “Italian food is very different from what we’re used to.”

“It’s tasty!” Yoshi offered up once his plate was clear. “Niichan, eat, eat. You’re so slow!”

“I was trying to be polite, Yoshi.” Tsuna sighed, and shrugged helplessly. Then Dino watched in slack-jawed, somewhat-disgusted awe as Tsuna consumed enough risotto for six men plus a rack of lamb in less time than it takes to  _say_  enough risotto for six men plus a rack of lamb. “... The food is very tasty though.”

/.../

“Stop it.” The illusion persisted. Hidetada, with a hole burned all the way through his chest, blood pooling under him. Iesada, the right side of his body mangled and crushed, discarded like a broken toy. Yoshimune, chest carved open by deep rents crossing shoulder to hip, eyes fixed sightlessly upwards. “ _STOP IT_.”

“Why don’t you make me?” The ghostly chuckle echoed out over the grisly scene. “Hm? Oh mighty Vongola Decimo. You think you can save them where all the others failed? A pathetic child like you?”

The snarl that ripped out of Tsuna’s throat was savage and wordless thing of wrath. The world shuddered, frozen under the weight of an enraged Sky. The Flames built, and  _built_ , consuming everything around Tsuna without pause. “ _Dai. **Entei.**_ ”

/.../

Watching a fireball bigger than the Iron Fort crash down the enemy base, Ryohei held Hidetada closer to his chest protectively.

“Oh, wow.” Grey eyes wide, Hide ignored Ryohei’s attempts to hold him still and climbed up over the boxer’s shoulders for a better view. “Niichan is  _pissed_.”

“ _Really_  pissed.” Iesada noted with a disturbing amount of bloodthirsty cheer. Kusakabe looked down at the younger boy in resigned dismay as the little blond Sky booted the body at his feet in the ribs. “Aren’t you glad you’re actually on our side, double agent-san?”

“He fell asleep when Niichan used his haki.” Yoshimune laughed from his spot on Hibari’s shoulders. “Ne, ne, did you see the fireball niichan made? It was huuuuuge!”

“Yes, very cool.” Gokudera agreed absently, most of his attention focused on the giant ball of flames that marked the position of his rampaging Sky. “... Well, there goes our food budget for the rest of the month... Eh. Well, there’s nothing to be done now. Juudaime’s going to be  _starving_  when he gets back. Somebody let Kyoko-hime know we’re probably going to need about three times the usual after-battle feast.”

“Sure thing, ‘Dera.” Yamamoto pulled out his phone to send a text, because Spanner was too busy recording the fight to use his even if it had better reception. “Is everybody else done with their fights?”

“Kufufufu~ all done.” Mukuro giggled gleefully from his seat on a pile of rubble. Chrome simply smiled and finished cleaning off the tines of her trident. “Life is always so interesting with dear Tsunayoshi.”

“Yeah.” Hide sighed a little wistfully as he watched the fire burn. “Niichan’s the best thing.”

=/=

**Author's Note:**

> Nana may or may not be Makino's reincarnation. Iemitsu may or may not be Shanks' reincarnation. Either way, neither of them remember any past lives so it's a moot point. It's just interesting to see how the idea that it was a possibility actually influenced the way I wrote the characters and their relationship. ♥
> 
> For the original tumblr prompt anonymous asked: " _If you're still doing your Ides of March prompts: Ace, Sabo and Luffy reborn as Iemitsu and Nana's kids or a One Piece and Harry Potter crossover. Feel free to ignore if the prompts are done._ "


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